Building a Heat Exchanger

Currently I'm running a open-loop HVC-style evaporative cooler, but I want to set up a closed loop to keep all the junk out of my blocks. Anyone got any good ideas for a heat exchanger? I was thinking about dropping 4ft of 1/2in copper tubing into the res and running the CPU loop through that, but wasn't sure how well it would work. Ideally I'm shooting for less than a 5*F delta between the res and CPU loop.

Copper loops would work but will require quite a few loops and add a pressure drop. I would suggest purchasing a 10 plate heat exchanger, running your current pump to it, and purchasing a new pump for your loop. Or simply add an inline filter to your current setup.

if you are using an open res (capacity?) and want to incorporate a closed CPU loop in it with a copper helix consider your ability to maintain ambient Delta t of your target of 5 degrees, this is dependant on the rapidity in which the water bath can change the temp of the CPU coolant, the flow rate in the loop within a safe Delta P at the loops narrowest point, not only with regard to loop rupture but post narrowing cavitation of gas out of solution. hope this helps

A heat exchanger can move an infinite amount of heat given an infinite delta between the two sides. If that example doesn't help, and I apologize, I mean to say that the so called "4 kilowatts" of load that it can "handle" is simply a measurement taken at a specific difference in temperature between the hot and cold loop. It does not mean it will handle 4 kw in a different temperature or application.

You will not have a very large delta between your loop and the bong loop.